Problem: Solve the equation. $ 25 = q + 20$ $q=$
Explanation: Subtract $20$ from both sides: 25 − 20 25 − 20 = = q q + 20 − 20 \begin{eqnarray} 25 &=& q &+ 20 \\ \\ {-20} && &{-20} \\\\ 25 {- 20} &=& q \end{eqnarray} Simplifying, we get: $ q = 5$